Automatic fire-alarm.



No. 754.555. PATENTED MAR. 15, 1904'.

M. K. PRED.

AUTOMATIC FIRE ALARM. APPLICATION P ILED MAB.. 9, 1903.

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No. r754,555.

UNITED STATES Patented March 15, 19u04.

PATENT OFFICE.

AUTOMATIC FIRE-ALARM.

SPECIFICATION forming part of Letters Patent No. 754,555, dated March15, 1904.

Application led March 9, 1903.

T all whom, t may concer-n:

Be it known that I, MASON K. FRED, a citizen of theUnited States,residing at Pleasanton, in the county of Atascosa and State of Texas,have invented a new and useful Automatic Fire-Alarm, of which thefollowing is a speciiication.

The invention relates .to certain improvements in automatic lire-alarmsystems of that general classin which the fusing of a currentconductingwire or the like establishes an electric circuit through an alarm of anydesiredv character.

The principal object of the invention is to provide a novel systemwhich, may be installed at small cost and in which a current-conductingwire having a low fusing-point is secured in position to the walls orceiling of a building where it will be exposed to intense heat in caseof lire, the wire closing the circuit through the battery, and thesevering of the wire at any point, either by fusion or cutting, willcause the sounding of an alarm.

With this and other objects in view the in vention consists in the novelconstruction and arrangement of parts herelnafter described, illustratedin the accompanying drawings, and

. particularly pointed outin the appended claim,

'it being understood that various changes in the form, proportions,si'ze, and minor details of the structure may be made without departingfrom the spirit or sacrificing any ofV the advantages of the invention.

In the accompanying drawings, Figure 1 is a diagram'of an automaticfire-alarm system arranged in accordance with the invention.

l Fig. 2 is a similar view illustrating a slightlyelectric energy beingsufficiently powerful to Serial No. 146,965. (No model.)

of the coils of the electromagnet and `the additional resistance-coil 5the current from the battery is shunted through the wires 6 and 7 andthe bell-magnets are not energized. Should a fire occur or an attempt bemade to destroy the alarm by severing the wires, the

The system is such as to permit the protection ofV a building of anysize by a single wire, which may be readily placed in position andsecured near all exposed points where tire would be likely to occur,while-the alarm may be placed at some central point in the building ormay be in the form of a relay for connection with the ordinary policefire-alarm system. In testing, the circuit closer 8 is opened in orderto break the circuit through the fusible wire. l

In the modified system shown in Fig. 2 a Wire of low resistance isemployed for a portion of the fusible circuit in order to decrease theresistance of the line, as where the fusible wire may be led oncethrough a room or rooms and the circuit completed by a nonfusible wireof higher conductivity. In Fig. 2 the wire 3 is a continuous wire ofmetal of a comparatively high conductivity extending between the polesof a battery and the binding-posts of the alarm to form a continuousclosed circuit, as before described. The wire 6/ leads from one of' thebell binding-posts through the room or rooms and is then connected withthe wire 3 at any desired point in order to complete the circuit. Thisarrangement of the system is useful in that less battery-power will berequired than can be employed where it is only necessary to lead currentwill instantly flow through the coils 'of the electromagnets and soundthe alarm.

IOO

a single Wire once through all of the rooms to be protected.

'Ihe fusible Wire may be formed of any desired metal or alloy, While theWires 3 and 4 are of course of higher conductivity, but preferably ofametal of comparatively high resistance. The resistance of the coilsWill depend on the length and resistance of the fusible Wire, and one ormore additional coils or other forms of resistance may be placed in theline when found necessary.

Having thus described my invention, what I clairn is- An automaticfire-alarm system comprising an alarm, a source `of electrical energyconnected direct in a closed circuit with said alarm, a Wire formed offusible metal extending throughout the room or rooms to be protected andalso connected in closed circuit with the battery, and artificialresistance connected in the line between the alarm and the point ofconnection of the fusible Wire with the battery, such resistance beinggreater than that offered by the fusible wire.

In testimony that I claim the foregoing as my own I have hereto affixedmy signature in the presence of two witnesses.

MASON K. FRED.

Witnesses:

W. M. ABERNETHY, ff H. G. MARTIN.

